Electromagnetic timepiece with oil shield



INVENTOR.

RTTORNEY J. BERGE ELECTROMAGNETIC TIMEPIECE WITH OIL SHIELD Filed Dec.11, 1944 Nov. 28, 1950 Patented Nov. 28, 1950 ELECTROMAGNETIC TIMEPIECEWITH OIL SHIELD Joseph Berge, Maplewood, N. J assignor to J aeger WatchCompany, Inc., New York, N. Y., a corporation of New York ApplicationDecember 11, 1944, Serial No. 567,688

l 3 Claims.

This invention relates to timing mechanisms, and more particularly tothat type of mechanism designed for embodiment in time clocks, or forassociation with other instruments to control the operation of thelatter at a predetermined time.

In a known type of timing mechanism the operation of the latter iseffected by electro-magnetic energy. For this purpose, there is employeda balance wheel which constitutes an armature, said balance wheel orarmature being connected with one side of a suitable source of current,such as a storage batter and having a contact pin adapted to engage aresilient contact finger that is connected with the opposite side ofsaid battery or current source. Engagement of the contact pin with thecontact finger, which occurs upon rotation of the armature in oppositedirections effected by the usual hair spring, completes the electriccircuit to a coil or solenoid which is then energized and creates anelectromagnetic force in two oppositely disposed pole pieces, whereuponthe armature or balance wheel is magnetically given an impulse in eachdirection, thereby sustaining the oscillations of said armatureindefinitely so long as .current is supplied to the timing mechanism.

The oscillations of the balance wheel are transmitted to a cam typeescapement member which is carried by the balance wheel staff adjacentthe contact pin and contact finger, and acts to intermittently rotate acooperating escapement wheel in one direction only, thereby controllingthe rate of movement of the usual reduction gears to effect operation oftime indicating means, or to effect operation of an associated device ata predetermined time.

In order to reduce frictional drag of the cooperating escapement wheeland member on the balance wheel and thus insure accurate operation ofthe timing mechanism, it is the usual practice to lubricate saidescapement member and wheel, as well as other parts of the mechanism,which is applied by the manufacturer upon assembling of said mechanism.The lubricant used is of a low viscosity to prevent congealing at lowtemperatures and drag on the timing mechanism, thereby insuring accurateoperation of the timing mechanism at all temperatures.

Usually, after a short period of operation of the timing mechanism, thelubricant on the escapement wheel and member creeps along the latter andalong the balance wheel staff onto the contact pin and contact finger.This objectionable result is aggravated when the timing mechanism isused in an inclined position, or when it is used with the balance wheelstaiT disposed vertically and Such that the contact pin and contactfinger are located beneath the escapement member. Under these conditionsthe lubricant on the contact pin and contact finger mixes with the scaleor oxide produced by the fine spark created thro h breaking of thecontacts and burning into the contact surfaces, and a paste or grease isthereby formed which acts as .an insulator and prevents flow of electriccurrent through the contacts to energize the coil, rendering the timingmechanism inoperative. It i then necessary to disassemble the timingmechanism and thoroughly clean the contacts before said mechanism can beof further use for its intended purp It is accordingly one object of thepresent invention to provide a timing mechanism of the magneticallyoperated type having novel means for preventing lubricant used in saidmechanism from affecting the accurate and efficient operation thereof,thus eliminating the difiiculty above referred to.

Another object of the invention is to provide a novel lubricantintercepting and absorbing member for an electromagnetic timingmechanism whereby the balance Wheel controlled contacts are maintainedfree from lubricant for effective operation of said mechanism.

A further object is to provide a novel metallic lubricant interceptingand absorbing member disposed between the escapement means and thecontacts of an electro-magnetic timing mechanism, whereby lubricant usedon said escapement means is prevented from "fou1ing said contacts andrendering said mechanism inoperative,

A still further object is to provide a novel lubricant intercepting andabsorbing member which may be incorporated in existing electro-magnetictiming mechanisms to prevent lubricant in said mechanism from foulingthe electrical contact means and rendering said mechanism inoperative.

The above and further objects and novel features of the presentinvention will more fully appear from the following detail descriptionwhen the same is read in connection with the accompanying drawings. Itis to be expressly understood, however, that the drawings are for thepurpose of illustration only, and are not intended as a definition ofthe limits of the invention, reference for this latter purpose being hadprimar-11y to the appended claims.

in the drawings. wherein like reference char ternally threaded toreceive a nut 59.

per end a nut from plate o acters refer to like parts throughout theseveral VIEWS,

Fig. 1 is a horizontal section of an electro-magnetic timing mechanismconstructed in accordance with the present invention, said section beingtaken on the line Il of Fig. 2;

Fig. 2 is a side elevation of the mechanism shown in Fig. l; and

Fig. 3 is an enlarged detail View of the balance wheel assembly shown inFigs. 1 and 2.

Referring to the drawings, the present invention is illustrated inconnection with a timing mechanism of the clock type particularlyadapted for installation in automobiles. As shown, said clock and timingmechanism comprise a balance wheel staff 5 journalled at its oppositeends in jeweled bearings (not shown) suitably. mounted in plates 6 andi. The latter are secured together in superposed spaced relation by twopillars 8, each having one end secured to plate is, and the opposite endextending through plate 6 and ex- Stafi 5 has fixed thereto adjacentplate l a hair spring H], one end of which is anchored in a stud llthree circumferentially spaced arcuate pallets l3. Arranged adjacent thepath of movement of pallets l3 are two oppositely disposed pole piecesl4 and i5 having wound thereon a coil or solenoid H5. Pole pieces id andit are en- P gaged over pillars S and fixedly held thereon in properposition relative to armature H: by spacers l1 surrounding said pillarsbetween said pole pieces and plate l.

Secured to armature l2 and extending downwardly therefrom is a contactpin 58 adapted to make contact with the free end of a resilient contactfinger l9 secured to a post as which, in turn, is secured to an arm 29.The latter is insulated from plate 5 and held thereon by a screw 22 thatextends upwardly through said plate and arm 2!, and has threaded on itsup- Screw 22 is also insulated and from a resistor 2d surrounding saidscrew between nut 23 and arm 2i.

between arm 2| and resistor 2 and a second conductor 26 leading fromsaid coil is connected between said resistor and nut 23. Screw 22 isconnected by a conductor 2'! to one side of a source of electric power28, the opposite side of said source being connected by a conductor 29to a threaded post 39 secured in plate 6. In commercial use, post asserves as the means for mounting the clock mechanism on the instrumentpanel of the automobile, and since said panel is grounded, the latterserves as the conductor 29 for connecting the mechanism with one side ofthe power source or storage battery 28. The magnetic circuit for theactuating solenoid l6 and pole pieces l4, l5 may thus be traced from oneside of battery 28 through conductor or panel 29, post 30, plate 6,pillars 8, plate 1, stud ll, hair spring ll], stafi 5, armature l2,contact pin !8, contact spring l9, post 20, arm 2|, conductor 25, coill6, conductor 26, nut 23, screw 25, and conductor 2'! to the oppositeside of battery 28. The resistor 24 being located between the conductors25 and 26 for coil [6 pro- A conductor 25 leading from coil I6 isconnected tects the contacts [8, [9 against burning during long use.

When no current is supplied to solenoid [6, the armature i2 is disposedwith its pallets l3 in the position shown in Fig. 1, and the contact pinis is engaged with contact finger [9. As- Sumii'lg now that battery 28is connected with screw 22 and post 36, oscillation of armature i2 isinitially started by conducting the current for an instant around thecontacts l8, 19 directly from plate 1 to post 20 by means of a manuallyoperated conductor (not shown) provided for this purpose. In this mannercoil It is subjected to the maximum energy of battery 28, and said coiland pole pieces l4, l5 are energized and magnetically whip the armature12 in a clockwise direction, as viewed in Fig. 1, thereby contractingand energizing hair spring H3, and breaking the circuit at l8, I9.Armature i2 is now rotated counter-clockwise (Fig. 1) by hair spring Hi,and the circuit is again closed for an instant by contacts 58, [9, againenergizing coil l6 and pole pieces :4, l5, whereupon armature i2 ismagnetically given an impulse in the counter-clockwise direction,thereby expanding and energizin hair spring l0. When the circuit isagain broken by relative movement of the contacts, spring l8 rotatessaid armature in a clockwise direction and the cycle is repeated as longas current is supplied to screw 22 and post 36, thereby sustaining theoscillations of armature or balance wheels 52 and stall 5.

The oscillations of armature l2 are transmitted to an escapement member3| (Fig. 3) secured to stafi 5 beneath said armature and the contacts l8and i9 and provided with two 0ppositely inclined cams 32 and 33 thatalternately engage successive teeth on an escapement wheel 3 (Fig. 2) toimpart intermittent movement to said wheel in one direction only. Theoperation of earns 32 and 33 is such that upon clockwise rotation ofarmature l2, cam 32 will engage a tooth on wheel 35 and move the latter,and upon counter-clockwise rotation of said armature, cam 33 will engagethe same tooth and further move said wheel, thereby moving wheel Be onetooth for each complete oscillation of armature l2.

Escapement wheel 34 is associated with and drives a worm 35, said wheeland worm being suitably journalled on plate 6. Worm 35 meshes with aworm gear 36 secured to a shaft 31 journalled in suitable bearings inplates 6 and l. Worm gear 35 drives a reduction gear train 38 includinggears 39 and 4B, for operating time indicating hands ll and 42relatively and accurately, said hands cooperating with a, dial 43carried by plate 6.

Novel means are provided for preventing the lubricant that must beapplied to cams 32 and 33 and to the teeth of escapement wheel 34 toreduce frictional drag on armature [2, from creepin along escapementmember 3! and fouling the contacts 58 and I9, said means serving tointercept and absorb the creeping lubricant before it can reach thecontacts I8 and i9. As shown, said lubricant intercepting and absorbingmeans or thwarter comprises a truncated cone-shaped disc 44 of adiameter larger than the diameter of escapement member 3! andsurrounding the balance wheel or armature staff 5 between saidescapement member and the contacts l8 and I9. Thwarter 44 is secured tostafi 5 for oscillation therewith by a push fit, and while it may bemade of any suitable absorbing material, it is preferably of a porousmetallic substance formed by compressing under comparatively heavypressure a mixture of powdered or granulated metallic ingredients, suchas copper and tin, the copper predominating, into a relatively hard andcompact mass, and thereafter heat treating said mass to form an alloy orbronze of a porous character. After heat treating, the porous metallicsubstance is sized to the desired diameter and bored out to provide acentral opening for reception of the staff 5. The porous metalliclubricant interceptor and absorber may also be made from a mixture ofcopper, tin and lead, or copper, tin and zinc, the copper in each casepredominating. Thwarter 44, due to its location and absorbing qualities,will thus not only intercept any lubricant creeping from the escapementmeans 3|, 34 before it can reach the contacts l8 and I9, but will alsoabsorb said lubricant, thereby further insuring that said contacts willbe maintained dry and free of lubricant for accurate and continuedoperation of the timing mechanism. In the illusstrated embodiment of theinvention, the diameter of the thwarter is substantially one andone-half times the diameter of escapement member 31, and the thicknessis substantially equal to two-thirds the distance between said memberand contact pin l8, the shape of the thwarter providing clearance forrotation of escapement wheel 34.

There is thus provided a timing mechanism of the electro-magnetic typewherein accurate and continued operation of the same is assured throughthe provision of novel means for preventing lubricant used in saidmechanism from getting on and fouling the circuit making and breakingcontacts thereof, said means preferably comprising a member made of aporous metallic substance and surrounding the balance wheel stafibetween the escapement means and the contacts, and acting to interceptand absorb any lubricant creeping from said escapement means before itcan reach said contacts. The lubricant intercepting and absorbing memberparticipates in the oscillation of the balance wheel stafi and,accordingly, it is not subject to any wear and will last indefinitely.Further, because of the metallic construction of the lubricantintercepting and absorbing member, the timing mechanism is not subjectedto any loose particles which will tend to clog or jam said mechanism.Additionally, the lubricant intercepting and absorbing memberconstitutes a new article of manufacture which can be incorporated inexisting electro-magnetic timing mechanisms to prevent lubricant in saidmechanism from fouling the contact members.

Although a single embodiment of the invention has been illustrated anddescribed in the foregoing specification, it is to be expresslyunderstood that changes may be made therein without departing from thespirit and scope of the invention, as will now be clear to those skilledin the art. For example, a member made of felt, leather or any otherabsorbing material may be substituted for the porous metallic member 44.Likewise, a disc having a depending skirt partially surrounding theescapement member 3| may also be used. Also, the size and shape of thethwarter 44 may be varied from that hereinbefore given to suit variousembodiments of said thwarter. For a definition of the limits of theinvention, reference is had primarily to the appended claims.

What is claimed is:

1. In a timing mechanism of the type having a staff, a balance wheel onsaid staff, electromagnetic means for imparting magnetic energy to saidwheel, means including a contact pin on said wheel for periodicallyconnecting a source of electric current with said electro-magneticmeans, and a lubricated escapement member carried by said staff adjacentsaid contact pin, the combination therewith of a porous metallic membernormally free of any lubricant and oscillatable with said staff anddisposed between said contact pin and said member.

2. In apparatus of the character described having a stafi, a balancewheel on said staff, electro-magnetic means for imparting magneticenergy to said Wheel, and circuit closing means under the control ofsaid wheel for periodically connecting a source of electric current withsaid electro-magnetic means, the combination therewith of a porousmetallic thwarter normally free of any lubricant and secured to theshaft for intercepting and absorbing lubricating oil creeping along saidshaft toward said circuit closing means.

3. A timepiece having a staff, a spring biasing the stafi in one angulardirection, electromagnetic means biasing the staff in the otherdirection, and an electric contact member carried by the staff andoperating to intermittently close and open the electro-magnetic circuit,a lubricated escapement on the stafi, and a finely porous metallic wallon the staff between the lubricated escapement and the contact.

JOSEPH BERGE.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 973,114 Haudenschild Oct. 18,1910 1,546,075 Horn July 14, 1925 1,826,719 Battegay Oct. 13, 19312,182,414 Tarbell Dec. 5, 1939 2,233,921 Junghans Mar. 3, 1941 OTHERREFERENCES Ser. No. 437,434, Quebatte et al. (A. P. (1.). published July13, 1943.

